Process of finishing paper



H. H. HANSON AND P. E. HODGDON.

PROCESS OF FINISHING PAPER. APPLICATION FILED JAN. 4, 1921.

Patented Jan. 3, 1922.

, also comprises top and bottom sheets or UNlTED stares HUGO H. HANSON, 013 BOSTON, MASSACHUSETTS, AND PAUL E. HODGDON, OF BAN MAINE, ASSIGNORS TO EASTERN MANUFACTURING COMPANY, OF CHUSETTS, A CORPORATION OF MASSACHUSETTS.

BOSTON, MASSA- PROCESS OF FINISHING'PAPER.

Specification of Letters Patent.

Application filed January 4, 1921. Serial No. 434,934.

and useful Improvements in Processes of- Finishing Paper, of which the following is av specification.

In the process of lawn-finishing or linenfinishing writing paper, it has heretofore been the custom to employ what is known as a plater, which comprises a pair of coacting press rolls capable of withstanding great pressure. Through these rolls is passed a stack which comprises sheets of properly tempered paper and sheets of linen or other textile fabric arranged in alternation. In addition to these sheets, the stack plates of iron or zinc, and sheets of zinc which at intervals are located throughout the stack, Ordinarily, in building the stack or book, upon a relatively thin sheet of iron 'is-placed first a sheet of zinc, then a sheet of textile fabric, then a sheet of paper, a sheet of textile fabric, and a sheet of zinc;'and,

by following this procedure, the stack or book-is built until approximately thirty or more such units are placed together. 'On

the top of the stack is then laid a sheet of iron, and the whole stack is passed between the press rolls one or more times to cause the irregular surfaces of the fabrics to become more or less embedded into the surfaces of the sheets of paper so as to impart thereto the desired finish. After the pressing operation has been completed, it is necessary to separate the various elements of the stack so that the sheets of zinc and fabric may be re-used in the formation of a second stack. The labor involved in, building the stack and separating it into its component elements is very great, and the wastage of the fabric sheets forms an element of great expense in the paper-finishing process. Furthermore, in forming the stacks, it is essential, of course, that the fabrics should not be wrinkled but should be spread evenly and without folds or pleats on the zincs and the sheets of paper as the stack is being formed. Furthermore, the edges or corners of the fabric sheets are cut and frayed by the zinc plates as the stack is passed between the rolls of the plater. Moreover at times the corners and the edges of the fabric sheets are frequently curled over, and spoil the cut or finish of the paper. After prolonged experimentation, we have found that it is possible, first to reduce the laborin- We have discovered that it is possible to secure the sheets of fabric to the zincs or z1nc plates, so that each zinc plate and its attached sheet of fabric may be handled as a unit in building the stack and disassembling the same. In other words, we have found that it is possible to glue or pasteto one or both faces of a sheet of zinc a sheet or sheets of the fabric so that they will be permanently attached thereto.

ur experimentation has demonstrated the fact that it is impractical to glue or paste the sheets of fabric to the zinc by a layer of glue or paste which covers the entire face of the zinc and the contacting face of the fabric. Due to the great pressure of the press rolls against the stack, and to the relative ductility of the zinc, the zines tend to becomefspread or elongated both longitudinally and laterally, and, when the entire surface of the fabric is cemented to the contacting surfaceof the zinc, the spreading of the zinc tears or cracks the fabric and renders it incapable of use without injury to the paper which is to be. finished thereby. We have'found that it is possible to prevent the cracking and tearing of the linen, and at the same time to accomplish the desired results, which we have hereinbefore mentloned, by. pasting only the marginal edges of the fabric sheets to the zinc plates. Preferably only the side marginal edges of the fabric sheets should be pasted to the zines, leaving the ends of the fabric sheets unpasted. 'By following this procedure, the

the stack. 7 V 7 0n the d1'flWlI1g;'tl1Q plater, wh ch 18 illustrated in Figure 1, comprises a suitable On the accompanying drawing,--'

Figurel illustrates,in perspective View, the ordinaryiplater, so called, which is used" in linen-finishing paper. I

Figure 2 illustrates a sheet of zinc to which is attached a sheet of textile fabricl Figure 3 represents'the same element but shows the opposite face thereof.

Figure 4- represents a transverse section through the sheet of zinc to which the sheets of textile fabric are secured. I

Figure. 5 represents, in endelevation, a portionof aistack or book which is built up of paper and the intervening sheetsof zinc and textile fabrics.

Figure 6 illustrates the first few units of fraine in V which is journaled the pressure rolls 10, 11, which are geared together by the gears 12,13. These rolls are rotated by the usual mechanism employed for that purpose which needs no description l'lGI'QliL.

The machine: is provided with a table it y upon which the stack or book may be placed,

and supported asit 1s being-passed back and forth between the pressure rolls. This ap paratus, as illustrated. and described, is the usual apparatus employedfor the purpose and does not differ therefrom. At 15 there is'shown. a stack or book ready-to be placed uponthe table and passed between the pres;

sure rolls l ve havefonnd that it is possible to carry out our invention by using the ordinary. zinc, plates which have heretofore been successfully employed, and to use any form of textile fabric or marker which has heretofore been utilized in linishingboth faces of. a sheet of paper.. Thusweunayemploy a. sheet 16 of n ne of the proper density or hardness, andsheets of linen or linen lawn or other equivalent material which has here tofore been successfully used. On both faces of each sheet 16 of zinc, we attach sheets 17,

1 18, of textile fabric, as shown in Figures :2,

and 4t; Preferably each sheet of textile fabe Ordinarily these "sheets are all oblong in face View, as shown in Figures 2 and 8,

' and they are of the sizes which are ordi:

narily employed. Each' sheet of textile fat;

' 'ric is secured by anarrow strip of glue,

paste or cement 19 along its side marginal. iodge to the surface of a zinc plate, so that there is secured to each zinc plate, except thoseemployed atthe bottoinand top of the stack, two sheets oftcxtilefabric l7 and 18 which cover both faces thereof, so'

finish ot the Lthat the zinc plate and its attached sheets cit-fabric may be handled as a; unit. iArny suitable form of paste, glue or cement may be utilizedfor the purpose. We havelfound,

.ior example, that ordinary animal glue may 1. Y l I we successiully used, but that there 1s at times a tendency for the glue to spoil the portion of the fabric sheet which is glued to the zinc, and we preiter to employ sodium paper where it (Werlapsthat sil'cate or a paste which we find on theopen market under the proprietary name of titiclr fast gum, we find that this does j not in ure in any way the finish of the paper.

Of course other forms of paste, glue 'or cement maybe-utilised as found ava lable.

.llefind itdesirable that the line of paste or glue, by which the sheets are cemented to the zines, shouldjbe asnarrow as possible without destroying the attachment of the fabric sheet to the zlnc. In actual practice,

we find that the line or paste should be.

appronimately one-half of an inch in width, and that, even thoughfthe marginal s de edges of the sheet should'have the finish -injured to some extent by reason of themesence of the glue, the subsequent trimming ofthe sheets of paper, which is customary, is sufticient to. remove any port ons of the sheet in which; thelimsh is notperfect, y

In. building the stack, the sameprocedure,

as has heretofore been followed, may; be practiced, except that it 'is unnecessary to handlese'paratelythe sheets. of fabric andf' the sheets of zinc. "Thatis tosay, the stack .orboolrmay be built by placing onaisheet of iron thebottom zinc which has a' sheet of fabric attached)to the. upperface thereof ,by the lines or stripes of glue; as herein described. sheetof paper of the proper tern-g .per, containing,;.say,}a,n1oisture content of 7%, is spread upon thesurfaceof the textile fabric, then upon this sheet otpaper is V placed a unit consisting of a" sheet of zinc with both facesv covered by sheets offabric, then a} sheet of paper, then. another zinc sheet unit, and so on until the stack or book is of the desired thickness. lEreferably "the top zinc ha only. its under face coveredwith the fabric. Then upon the top of the pile is placed the usual iron-plate and the book is now readyfor passage between the rolls of the plate. y 7

It will be. understood, of course, that, when the book is passed between the-rolls,

tudinal of the lines: or stripes; of paste. or glue.

' It is not essential .that the sheets 'of linen shouldbe stretched'tautfbetween their side edgeswhen securingthemto thezinc plates,

although, of-course, is sesame that they should be spread upon; the surface of the zinc plates so as to form no wrinkles or pleats. Consequently, when the zines spread 120 the book or stack travels in adirectionlongiafter continued use, the fabrics are capable of stretching to some extent and are thus preventedf from tearing.

We have found in actual practice that, by following-. the procedure herein described, the length of life of the linen sheets may be greatly prolonged and that there ispractically little wastage of the fabric sheets due to fraying, tearing or becoming wrinkled. Inasmuch. aS one of the heaviest. expenses borne in the finishing of writing paper is the cost of the fabric sheets, we have, by'the procedure herein described, effected great saving in the cost of finishing. We have found, with the same number of operatives, that it is possible to secure an increase in production of at least 25% and that the fabric sheets have a length of life approximately three times those which are employed without attachment to the zinc plates.

What we claim is:

1. A process of surface-finishing paper, which comprises pasting sheets of textile fabric only alon their side edges to com plemental metallic sheets, placing a sheet of paper between the metallic sheets in facial engagement with the textile sheets, and subjecting the book thus formed to progressive or rolling pressure longitudinal-0f the side edges of said sheets.

2. For use in surface-finishing. paper, a flat metallic sheet, a sheet of textile fabric spread over the surface of the metallic sheet, and lines or stripes of adhesiveinaterial cementing said sheets togetherqjonly along their side edges. 6- 1 3. For use in surface-finishing paper, a flat metal sheet, sheets of textile fabric spread over both faces of said metallic sheet, and lines or stripes of adhesive material cementing such sheets together only along their side edges.

4. A book or stack ready forsubjecting to the rolls of a plater, comprising a plurality of superposed sheets of paper and interposed units, each unit including a middle sheet of metal and outer textilel-fabric sheets cemented thereto only along their side edges. T

In testimony whereof we have aifixed our signatures.

HUGO H. HANSON. PAUL E. HODGDON. 

